Joint structure and pipe joining method

Abstract

To provide a joint structure that reduces the burden on workers and allows for easy and efficient joining of pipes to be joined. [Solution] The joint structure 1 is a joint structure 1 having a socket 3 of a pipe W2, a receiving opening 2 of a pipe to be joined to pipe W2, and an annular sealing member 20 that seals the space between the outer circumferential surface 3a of the socket 3 of pipe W2 and the inner circumferential surface 2a of the receiving opening 2 of the pipe to be joined W1. The joint structure 1 has an annular socket contact member 50 fixed to the inner circumferential surface 2a of the receiving opening 2 of the pipe to be joined W1 at a position closer to the opening H of the receiving opening 2 of the pipe to be joined W1 than the sealing member 20, so as to contact the surface of the outer circumferential surface 3a of the socket 3 that is located closer to the opening H of the receiving opening 2 of the pipe to be joined W1 than the surface in contact with the sealing member 20.

Description

Technical Field

[0001] The present invention relates to a joint structure and a pipe joining method having a pipe insertion port, a receiving port of a joined pipe joined to the pipe, and an annular seal member that seals between the outer peripheral surface of the pipe insertion port and the inner peripheral surface of the receiving port of the joined pipe.

Background Art

[0002] A pipe joint structure having a seal member between the outer peripheral surface of a pipe insertion port and the inner peripheral surface of a receiving port of a joined pipe is known. For example, in Patent Document 1, an insertion port formed at an end of one pipe is inserted into a receiving port formed at an end of the other pipe, and an annular seal material is disposed in a seal material accommodation groove formed on the inner periphery of the receiving port, and the seal material is compressed between the receiving port and the insertion port to seal between the receiving port and the insertion port. A detachment prevention pipe joint is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in such a joint structure, when the insertion port of the pipe is inserted into the receiving port of the joined pipe, the seal member attached to the receiving port of the joined pipe contacts the outer peripheral surface of the insertion port of the pipe. Therefore, in order to smoothly insert the insertion port into the receiving port, it is necessary to apply a lubricant that reduces frictional resistance to the insertion port of the pipe or the seal member. Further, if foreign matter or the like adheres to the outer peripheral surface of the insertion port, the seal member may be damaged when the insertion port is inserted into the receiving port.

[0005] Therefore, before inserting the spigot of the pipe into the socket of the pipe to be joined, it is necessary to perform pretreatment, such as removing foreign matter like soil and dust adhering to the outer surface, or applying a lubricant to the outer surface to reduce frictional resistance with the sealing member. This pretreatment is performed by workers in the excavated trench where the pipe is laid.

[0006] Therefore, there is a need for a joint structure that allows the worker to easily and efficiently perform the pretreatment on the outer surface of the pipe insertion port without having to enter the excavated trench, and that can be used on both the pipe insertion port and the receiving port of the pipe to be joined.

[0007] The objective of the present invention is to provide a joint structure that reduces the burden on the worker and allows for easy and efficient joining of the spigot end of a pipe and the socket end of a pipe to be joined. [Means for solving the problem]

[0008] A joint structure according to one embodiment of the present invention is a joint structure having a pipe spigot, a receiving end of a pipe to be joined to the pipe, and an annular sealing member that seals the space between the outer circumferential surface of the pipe spigot and the inner circumferential surface of the receiving end of the pipe to be joined. The joint structure has an annular spigot contact member fixed to the inner circumferential surface of the receiving end of the pipe to be joined at a position closer to the receiving end of the pipe to be joined than the sealing member, so as to contact the outer circumferential surface of the spigot that is located closer to the receiving end of the pipe to be joined than the surface on which the sealing member is in contact (first configuration).

[0009] According to the above configuration, when joining a pipe to a pipe to be joined, the insertion opening contact member contacts the outer surface of the insertion opening before the insertion opening of the pipe contacts the sealing member.

[0010] This allows the pre-treatment, such as removing foreign matter adhering to the outer surface of the Socket and applying lubricant, which is performed by the Socket Contact Member contacting the outer surface of the Socket, to be carried out simultaneously with the insertion of the Socket of the pipe into the Socket of the pipe to be joined. Therefore, the work of joining the Socket of the pipe to be joined and the Socket of the pipe can be carried out efficiently. Moreover, in a joint structure having the above configuration, the pre-treatment of the Socket of the pipe does not need to be performed by an operator in the excavated trench where the pipe is placed.

[0011] Therefore, it is possible to provide a joint structure that reduces the burden on workers and allows for easy and efficient joining of the pipe and the pipe to be joined.

[0012] In the first configuration described above, the socket contact member includes an annular foreign matter removal portion for contacting the outer circumferential surface of the socket and removing foreign matter adhering to the outer circumferential surface of the socket (second configuration).

[0013] As a result, when the pipe insertion end is inserted into the pipe to be joined, the foreign matter removal section can remove foreign matter such as dirt and dust adhering to the outer surface of the pipe insertion end. Therefore, the burden on the worker to remove foreign matter from the outer surface is reduced, and a joint structure is provided that allows the pipe and the pipe to be joined to be joined easily and efficiently.

[0014] In the second configuration described above, the insertion port contact member is located further away from the receiving port opening than the foreign matter removal portion and further includes an annular lubricant application portion for contacting the outer circumferential surface of the insertion port and applying a lubricant (third configuration).

[0015] As a result, when inserting the pipe's spigot into the pipe to be joined, the lubricant is applied by the lubricant application unit to the outer surface of the pipe's spigot after the foreign matter has been removed by the foreign matter removal unit, thereby joining the pipe and the pipe to be joined. Therefore, it is possible to provide a joint structure that reduces the burden on the worker in removing foreign matter and applying lubricant, and allows the pipe and the pipe to be joined to be joined easily and efficiently.

[0016] In the third configuration described above, the joint structure further includes an annular mounting member on the inner circumferential surface of the pipe to be joined for attaching the sealing member. The foreign matter removal portion and the lubricant application portion are each mounted on the inner circumferential surface of the mounting member at a position closer to the socket opening of the pipe to be joined than the sealing member, and are arranged axially in that order from the socket opening toward the axially inward side of the socket (fourth configuration).

[0017] This allows the foreign matter removal section, lubricant application section, and sealing member to be arranged sequentially from the receiving opening of the pipe to be joined toward the axial inward direction of the receiving opening. Furthermore, by attaching the sealing member to the inner circumferential surface of the pipe to be joined using the mounting member, and by attaching the foreign matter removal section and lubricant application section to the inner circumferential surface of the mounting member, the foreign matter removal section, the lubricant application section, and the sealing member can be attached to the inner circumferential surface of the pipe to be joined by the mounting member.

[0018] Therefore, a joint structure that allows joining the pipe and the pipe to be joined while removing foreign matter from the outer surface of the pipe's insertion point and applying lubricant can be more easily realized.

[0019] In the fourth configuration described above, at least one of the foreign matter removal section and the lubricant application section is arranged to overlap radially with respect to the mounting member and the sealing member (fifth configuration).

[0020] This makes it possible to achieve a configuration in which the foreign matter removal section and the lubricant application section can be arranged more compactly in the axial direction of the pipe to be joined, relative to the sealing member and the mounting member. Therefore, with the above configuration, the sealing function by the sealing member and the functions of removing foreign matter and applying lubricant to the outer surface of the insertion opening by the foreign matter removal section and the lubricant application section can be achieved within the receiving opening, while shortening the axial length of the receiving opening. Thus, the overall length of the pipe to be joined can be shortened while achieving the above functions.

[0021] In the fourth configuration, the inner peripheral surface of the mounting member includes an inclined surface whose inner diameter decreases in the insertion direction of the tube from the end on the receiving port opening side. The foreign matter removing portion is elastically deformable in the radial direction and is fixed on the inner peripheral surface of the inclined surface (sixth configuration).

[0022] Thus, when inserting the insertion port of the tube into the receiving port of the joined tube, the elastic restoring force received by the outer peripheral surface of the insertion port from the foreign matter removing portion is small when the insertion port passes through the end on the receiving port opening side of the mounting member, and increases as the insertion port is inserted axially inward of the joined tube. Therefore, the insertion port of the tube can be easily inserted into the joined tube, and foreign matter adhering to the outer peripheral surface of the insertion port can be more reliably removed by the foreign matter removing portion.

[0023] Therefore, when joining the insertion port of the tube to the receiving port of the joined tube, the workability can be improved while more reliably removing foreign matter adhering to the outer peripheral surface of the insertion port.

[0024] A tube joining method according to an embodiment of the present invention is a tube joining method for joining an insertion port of a tube and a receiving port of a joined tube such that an annular seal member seals between the outer peripheral surface of the insertion port of the tube and the inner peripheral surface of the receiving port of the joined tube. The tube joining method includes a seal member mounting step of mounting the seal member on the inner peripheral surface of the receiving port of the joined tube, an insertion port contact member fixing step of fixing an annular insertion port contact member having an inner diameter equal to or smaller than the outer diameter of the insertion port of the tube at a position closer to the receiving port opening of the joined tube than the seal member with respect to the inner peripheral surface of the receiving port of the joined tube, and a tube joining step of inserting the insertion port of the tube into the receiving port of the joined tube while bringing the outer peripheral surface of the insertion port of the tube into contact with the inner peripheral surface of the insertion port contact member and the seal member in this order to join the tube and the joined tube (first method).

[0025] According to the above method, when joining a tube to a joined tube, the insertion port contact member contacts the outer peripheral surface of the insertion port before the insertion port of the tube contacts the seal member.

[0026] As a result, it is possible to simultaneously perform pre - treatment such as removing foreign matter adhering to the outer peripheral surface of the insertion port and applying a lubricant by bringing the insertion port contact member into contact with the outer peripheral surface of the insertion port, and the operation of inserting the insertion port of the pipe into the receiving port of the joined pipe. Therefore, the operation of joining the receiving port of the joined pipe and the insertion port of the pipe can be performed efficiently. Moreover, in the joint structure having the above - described configuration, it is not necessary for an operator to perform the pre - treatment on the insertion port of the pipe in the excavation groove where the pipe is arranged.

[0027] Therefore, it is possible to provide a pipe joining method that reduces the burden on the operator and can easily and efficiently join the pipe and the joined pipe.

[0028] In the first method, the insertion port contact member includes an annular foreign - matter removing portion for removing foreign matter adhering to the outer peripheral surface of the insertion port of the pipe and an annular lubricant - applying portion for applying a lubricant to the outer peripheral surface. In the insertion port contact member fixing step, the insertion port contact member is fixed to the inner peripheral surface of the joined pipe so that the foreign - matter removing portion, the lubricant - applying portion, and the seal member are arranged in order axially from the receiving - port opening of the joined pipe toward the inner side in the axial direction of the receiving port. The pipe joining step includes a foreign - matter removing step of removing foreign matter adhering to the outer peripheral surface of the insertion port by bringing the outer peripheral surface of the insertion port into contact with the inner peripheral surface of the foreign - matter removing portion when the insertion port of the pipe is inserted into the receiving port of the joined pipe, and a lubricant - applying step of applying the lubricant to the outer peripheral surface by bringing the outer peripheral surface of the insertion port, which was contacted by the foreign - matter removing portion in the foreign - matter removing step, into contact with the inner peripheral surface of the lubricant - applying portion when the insertion port of the pipe is further inserted into the receiving port of the joined pipe (second method).

[0029] As a result, when the pipe's insertion end is inserted into the pipe to be joined, the foreign matter removal unit can remove foreign matter such as dirt and dust adhering to the outer surface of the pipe's insertion end. In addition, after the foreign matter has been removed by the foreign matter removal unit, a lubricant can be applied to the outer surface of the pipe's insertion end by the lubricant application unit, allowing the pipe and the pipe to be joined to be connected. Therefore, a pipe joining method can be provided that reduces the burden on the worker in removing foreign matter and applying lubricant, allowing the pipe and the pipe to be joined to be connected easily and efficiently.

[0030] In the second method described above, in the insertion port contact member fixing step, the foreign matter removal portion and the lubricant application portion are attached to the inner surface of an annular mounting member that fixes the sealing member on the inner surface of the pipe to be joined, such that the foreign matter removal portion and the lubricant application portion are positioned closer to the receiving port opening of the pipe to be joined than the sealing member, and are aligned in the axial direction from the receiving port opening toward the axial inward side of the receiving port (third method).

[0031] This allows the foreign matter removal section, lubricant application section, and sealing member to be arranged sequentially from the receiving opening of the pipe to be joined toward the axial inward direction of the receiving opening. Furthermore, by fixing the sealing member on the inner circumferential surface of the pipe to be joined with the mounting member, and by attaching the foreign matter removal section and the lubricant application section on the inner circumferential surface of the mounting member, the foreign matter removal section, the lubricant application section, and the sealing member can be fixed on the inner circumferential surface of the pipe to be joined by the mounting member.

[0032] Therefore, a pipe joining method is provided that allows for easy and efficient joining of the pipe and the pipe to be joined while removing foreign matter from the outer surface of the pipe's insertion opening and applying a lubricant. [Effects of the Invention]

[0033] A joint structure according to one embodiment of the present invention has an annular Socket Contact Member fixed to the inner Circumferential Surface of the Socket of the Pipe to be Joined at a position closer to the Socket Opening of the Pipe to be Joined than the sealing member, so as to contact the outer circumferential surface of the Socket that is located closer to the Socket Opening of the Pipe to be Joined than the surface on which the sealing member is in contact with the Socket.

[0034] This allows the pre-treatment, such as removing foreign matter adhering to the outer surface of the Socket and applying lubricant, by having the Socket Contact Member contact the outer surface of the Socket, to be performed simultaneously with the insertion of the Socket of the pipe into the receiving end of the pipe to be joined. Therefore, it is possible to provide a joint structure that reduces the burden on the worker and allows the pipe and the pipe to be joined to be joined easily and efficiently. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 is an end view showing the schematic configuration of the joint structure. [Figure 2] Figure 2 is a partially enlarged view of the end face of the joint structure in Figure 1. [Figure 3] Figure 3 is a flowchart showing the pipe joining method. [Figure 4A] Figure 4A is a schematic cross-sectional view showing how a sealing member is placed within the socket groove of the socket of the pipe to be joined. [Figure 4B] Figure 4B is a schematic cross-sectional view showing how a mounting member with an insertion contact member attached is installed inside a pipe to be joined where a sealing member is located. [Figure 4C] Figure 4C is a schematic cross-sectional view showing how a pipe with foreign matter attached to the outer surface of its socket is inserted into the socket of a pipe to be joined, to which a socket contact member is attached. [Figure 4D] Figure 4D is a schematic cross-sectional view showing how a tube is inserted into the socket while removing foreign matter adhering to the outer surface of the socket using the foreign matter removal unit. [Figure 4E]Figure 4E is a schematic cross-sectional view showing how a pipe is inserted into a socket by applying lubricant to the outer surface of the socket from which foreign matter has been removed, while simultaneously bringing the outer surface of the socket into contact with the contact portion of the sealing member. [Figure 4F] Figure 4F is a schematic cross-sectional view showing the state in which the pipes to be joined and the pipes are joined together. [Modes for carrying out the invention]

[0036] The embodiments will be described below with reference to the drawings. In each drawing, the same parts are denoted by the same reference numerals, and the description of those parts will not be repeated. Note that the dimensions of the components in each drawing do not faithfully represent the dimensions of the actual components or the dimensional ratios of each component.

[0037] In the following explanation, the direction in which the axis P of the pipe to be joined extends is referred to as the axial direction, the direction perpendicular to the axial direction is referred to as the radial direction, and the direction along the arc centered on the axis P is referred to as the circumferential direction. In the joint structure 1, the axis P of the pipe to be joined and the axis of pipe W2 coincide.

[0038] Furthermore, in the following explanation, the expressions "fix," "connect," and "attach" (hereinafter referred to as "fixing, etc.") include not only cases where components are directly fixed to each other, but also cases where they are fixed to each other via other components. In other words, in the following explanation, the expressions "fixing, etc." include both direct and indirect fixing of components to each other.

[0039] (Joint structure) Figure 1 is an end view showing the schematic configuration of the joint structure 1. Note that Figure 1 is an end view of the joint structure 1 when it is cut axially by a plane containing the axis P of the pipe to be joined W1. Figure 2 is a partially enlarged view of the end view of the joint structure 1 in Figure 1. Note that the radial gap between the sealing portion 22 of the sealing member 20 and the outer circumferential surface 3a of the insertion opening 3 of the pipe W2 in Figure 2 is exaggerated to represent the lubricant K. Therefore, in reality, the sealing portion 22 of the sealing member 20 is in close contact with the outer circumferential surface 3a of the insertion opening 3.

[0040] As shown in Figures 1 and 2, the joint structure 1 includes a socket 3 of pipe W2, a receiving end 2 of the pipe to be joined W1, a sealing member 20, a mounting member 30, and a socket contact member 50. The sealing member 20 seals the space between the inner circumferential surface 2a of the receiving end 2 and the outer circumferential surface 3a of the socket 3. The mounting member 30 is a member for fixing the sealing member 20 onto the inner circumferential surface 2a of the receiving end 2 and for fixing the socket contact member 50 to the inner circumferential surface 2a of the receiving end 2.

[0041] Pipe W2 and the pipe to be joined W1 are, for example, water pipes. Pipe W2 and the pipe to be joined W1 may be pipes other than water pipes, such as sewer pipes, agricultural water pipes, or gas pipes. Pipe W2 and the pipe to be joined W1 may be ductile cast iron pipes, other metal pipes, or resin pipes.

[0042] Pipe W2 has a socket 3 at its other axial end. The pipe to be joined W1 has a socket 2 at one axial end into which the socket 3 of pipe W2 can be inserted. The socket end 12 located at one axial end of the socket 2 has an opening H. The socket 3 of pipe W2 is inserted axially into the socket 2 through the opening H of the socket end 12 to form the joint structure 1.

[0043] The Socket 3 in pipe W2 is the portion of pipe W2 that radially overlaps with pipe W1 in the joint structure 1 where pipe W2 and pipe W1 are joined. In other words, the Socket 3 is located within the Receptacle 2 of pipe W1 in the joint structure 1. As will be described in more detail later, foreign matter G has been removed from the outer surface 3a of the Socket 3 of pipe W2 in the joint structure 1.

[0044] As shown in Figure 1, the socket 2 of the pipe to be joined W1 has a lock ring groove 14 and a socket groove portion 15 on its inner circumferential surface 2a. The socket groove portion 15 is located on the opening side of the socket 2, relative to the lock ring groove 14.

[0045] The locking ring groove 14 is an annular groove provided around the entire circumference. A locking ring M is positioned within the locking ring groove 14. The locking ring M positioned within the locking ring groove 14 restricts the insertion end 3 of the pipe W2, which is inserted into the receiving end 2 of the pipe W1 to be joined, from coming out of the receiving end 2. The configuration of the locking ring groove 14 and the locking ring M is the same as that of a typical locking ring groove and locking ring. Therefore, a description of the locking ring groove 14 and the locking ring M is omitted.

[0046] The receiving groove portion 15 is an annular groove extending circumferentially on the inner circumferential surface 2a of the receiving opening 2. As shown in Figure 2, the receiving groove portion 15 has a substantially rectangular cross-section. The receiving groove portion 15 is located on the inner circumferential surface 2a adjacent to the inner circumferential surface 12a of the receiving end portion 12 in the other axial direction. The receiving groove portion 15 contains the receiving groove insertion portion 21 of the sealing member 20, which will be described later, and the protruding portion 33 of the mounting member 30, which will be described later.

[0047] (Sealing material) The sealing member 20 is positioned between the inner circumferential surface 2a of the receiving opening 2 and the outer circumferential surface 3a of the insertion opening 3. The sealing member 20 is positioned within the receiving opening groove 15 provided on the inner circumferential surface 2a of the receiving opening 2.

[0048] The sealing member 20 is made of an elastic material such as rubber. The sealing member 20 is an annular member in which the axis of the sealing member 20 coincides with or is parallel to the axis P of the pipe W1 to be joined. As shown in Figure 2, the sealing member 20 has an insertion portion 21 into the receiving groove and a sealing portion 22.

[0049] The insertion portion 21 within the receiving groove is annular and inserted into the receiving groove portion 15. The axial length of the insertion portion 21 is shorter than the width (axial length) of the receiving groove portion 15. In addition to the insertion portion 21, the protruding portion 33 of the mounting member 30, which will be described later, is also positioned within the receiving groove portion 15. As a result, the insertion portion 21 is axially sandwiched between the protruding portion 33 of the mounting member 30 and the side surface of the receiving groove portion 15.

[0050] The insertion portion 21 within the receiving groove is pressed radially outward against the bottom surface of the receiving groove portion 15 by the retaining portion 311 of the mounting member 30. As a result, the insertion portion 21 within the receiving groove portion 21 is fixed to the receiving groove portion 15 by the mounting member 30.

[0051] The sealing portion 22 is annular in shape and protrudes radially inward from the radially inner side of the insertion portion 21 within the receiving groove and from the other axial end. The sealing portion 22 is made of an elastic material such as rubber that is more easily deformable than the insertion portion 21 within the receiving groove.

[0052] The minimum inner diameter of the sealing portion 22 when the insertion port 3 is not inserted into the receiving port 2 is smaller than the outer diameter of the insertion port 3. As a result, the sealing portion 22 is configured to contact the insertion port 3 when the insertion port 3 is inserted into the receiving port 2.

[0053] The sealing portion 22 has a contact portion 22a that contacts the outer circumferential surface 3a of the insertion port 3. A lubricant K is applied to the outer circumferential surface 3a of the insertion port 3 that the contact portion 22a contacts. The lubricant K reduces the frictional resistance generated between the outer circumferential surface 3a of the insertion port 3 and the contact portion 22a when the contact portion 22a contacts the outer circumferential surface 3a of the insertion port 3. This allows the outer circumferential surface 3a of the insertion port 3 to slide smoothly against the contact portion 22a, while the insertion port 3 pushes the sealing portion 22 in the other axial direction.

[0054] In this way, the sealing portion 22 is held so as to extend axially while being sandwiched radially between the inner circumferential surface 2a of the receiving end 2 of the pipe W1 to be joined and the outer circumferential surface 3a of the insertion end 3 of the pipe W2. As a result, the sealing portion 22 can axially seal the space between the inner circumferential surface 2a of the receiving end 2 and the outer circumferential surface 3a of the insertion end 3.

[0055] (Mounting components) The mounting member 30 is a member for fixing the sealing member 20 and the insertion contact member 50 to the inner circumferential surface of the receiving opening 2. The mounting member 30 is an arc-shaped member that has a slit in a part of its circumferential direction and is elastically deformable in the radial and circumferential directions, although it is not specifically shown in the figures. Before being installed inside the pipe to be joined W1, the mounting member 30 has an outer diameter larger than the inner diameter of the insertion portion 21 of the sealing member 20 into the receiving groove.

[0056] The mounting member 30 is elastically deformable in the radial and circumferential directions to narrow the circumferential spacing of the slits. This allows the mounting member to be elastically deformed in the radial and circumferential directions to narrow the circumferential spacing of the slits and inserted into the socket 2 from the socket end 12. Moreover, when the mounting member 30 is positioned on the inner circumferential surface of the socket 2, it attempts to return to its original shape due to its elastic restoring force. Therefore, this elastic restoring force presses the sealing member 20 radially outward, as will be described in more detail later.

[0057] The mounting member 30 has a main body portion 31, a protruding portion 33, and the slit. The main body portion 31 is positioned outside the receiving groove portion 15, overlapping with the receiving groove portion 15 and the receiving end portion 12 when viewing the pipe to be joined W1 radially. The main body portion 31 is cylindrical in shape and extends in the axial direction. The main body portion 31 has a pressing portion 311 and a receiving contact portion 321.

[0058] The pressing portion 311 is located on the opposite axial side of the main body portion 31. The pressing portion 311 is located adjacent to the sealing portion 22 in the axial direction. The pressing portion 311 is located outside the receiving groove portion 15, and when viewed radially across the pipe to be joined W1, it is positioned to overlap with the receiving groove portion 15. The pressing portion 311 is in contact with the inner circumferential surface 21a of the receiving groove insertion portion 21 of the sealing member 20 inserted into the receiving groove portion 15. The pressing portion 311, by the elastic restoring force described above, presses the receiving groove insertion portion 21 of the sealing member 20 radially outward relative to the bottom surface of the receiving groove portion 15.

[0059] The socket contact portion 321 is located on one axial side of the mounting member 30. The socket contact portion 321 extends axially from the pressing portion 311. When viewing the pipe to be joined W1 radially, the socket contact portion 321 is positioned to overlap with the inner circumferential surface 12a of the socket end portion 12. The socket contact portion 321 is in contact with the inner circumferential surface 12a of the socket end portion 12.

[0060] The protruding portion 33 projects radially outward from the entire circumference of the outer surface of the main body portion 31 toward the receiving groove portion 15. The protruding portion 33 is positioned within the receiving groove portion 15 toward the opening H side of the receiving opening 2 than the receiving groove insertion portion 21. The protruding portion 33 is in axial contact with one axial side surface within the receiving groove portion 15 and the receiving groove insertion portion 21. As a result, the protruding portion 33 axially clamps the receiving groove insertion portion 21 between itself and the other axial side surface of the receiving groove portion 15, thereby fixing the receiving groove insertion portion 21 axially relative to the receiving groove portion 15. In this embodiment, the entire protruding portion 33 is located within the receiving groove portion 15. However, only a part of the protruding portion may be located within the receiving groove portion.

[0061] According to the above configuration, the protruding portion 33 axially sandwiches the insertion portion 21 of the sealing member 20 into the receiving groove between itself and the other axial side surface of the receiving groove portion 15, and the pressing portion 311 is located on the opening H side of the sealing portion 22.

[0062] As a result, even if a force is applied to the sealing member 20 that causes it to move axially toward the opening H, for example, due to water pressure inside the pipe W1 to be joined, the protruding portion 33 can restrict the axial movement of the insertion portion 21 within the receiving groove portion 15, and the retaining portion 311 can restrict the axial movement of the sealing portion 22.

[0063] In addition, in the above configuration, the pressing portion 311 presses the insertion portion 21 into the receiving groove radially outward against the bottom surface of the receiving groove portion 15. Moreover, the receiving contact portion 321 is in contact with the inner circumferential surface 12a of the receiving end portion 12, and the protruding portion 33 is in contact with one axial side surface of the receiving groove portion 15.

[0064] As a result, even if a force is applied to the sealing portion 22 that causes the insertion portion 21 of the sealing member 20 into the receiving groove to move radially inward, for example, due to water pressure inside the pipe W1 to be joined, the retaining portion 311 can restrict the radial movement of the insertion portion 21 into the receiving groove.

[0065] Furthermore, even if the retaining portion 311 is pushed radially inward by the insertion portion 21 within the receiving groove, the receiving contact portion 321 contacts the inner circumferential surface 12a of the receiving end portion 12 and the protruding portion 33 contacts one axial side of the receiving groove portion 15, thereby restricting the radially inward movement of the mounting member 30. This allows the sealing member 20 to be held radially.

[0066] Therefore, the mounting member 30 can restrict the axial and radial movement of the sealing member 20.

[0067] The main body portion 31 of the mounting member 30 is configured so that the insertion port contact member 50 can be attached to its inner circumferential surface 31a. For attaching the insertion port contact member 50 to the inner circumferential surface 31a of the main body portion 31, known configurations such as bonding with adhesive or adhesive tape, or bonding with a joining member such as resin can be employed.

[0068] The inner circumferential surface 31a of the main body 31 has an inclined surface 32a on the opening H side of the receiving port 2. The inclined surface 32a is a surface that changes so that the inner diameter of the main body 31 decreases from one axial end toward the other axial end, which is the insertion direction of the insertion port 3 of the pipe W2. In other words, the inner diameter of the main body 31 on the opening H side of the receiving port 2 decreases from one axial end of the main body 31 toward the other axial end.

[0069] (Insertion port contact member) The socket contact member 50 is a member that contacts the outer circumferential surface 3a of the socket 3 when the socket 3 is inserted into the socket 2. As described above, the socket contact member 50 is attached to the inner circumferential surface 31a of the mounting member 30, and is therefore fixed to the inner circumferential surface 2a of the socket 2 via the mounting member 30.

[0070] The socket contact member 50 is annular in shape, and its inner diameter is smaller than the outer diameter of the socket 3. Therefore, when the socket 3 is inserted into the socket 2, the socket contact member 50 comes into contact with the outer circumferential surface 3a of the socket 3.

[0071] The Socket Contact Member 50 is positioned on the inner circumferential surface 2a of the Socket 2 of the pipe W1 to be joined, closer to the opening H than the sealing portion 22 of the sealing member 20. More specifically, the Socket Contact Member 50 is fixed to the inner circumferential surface 2a of the Socket 3 so as to contact the surface of the outer circumferential surface 3a of the Socket 3 that is closer to the opening H than the surface to which the contact portion 22a of the sealing portion 22 makes contact. The Socket Contact Member 50 performs pre-treatment on the outer circumferential surface 3a of the Socket 3, such as removing foreign matter G and applying lubricant K. Specifically, the Socket Contact Member 50 has a foreign matter removal portion 51 and a lubricant application portion 52.

[0072] (Foreign object removal section) The foreign matter removal section 51 is a component that contacts the outer circumferential surface 3a of the insertion opening 3 inserted into the receiving opening 2, and removes foreign matter G adhering to the outer circumferential surface 3a of the insertion opening 3.

[0073] Foreign matter G is, for example, dust and dirt that adheres to the outer surface 3a of the insertion opening 3 when the pipe W2 is laid in the excavated trench. Foreign matter G may be a solid other than dust or a liquid, as long as it can adhere to the outer surface 3a of the insertion opening 3.

[0074] The foreign matter removal section 51 is attached to the inner circumferential surface 31a of the mounting member 30 so as to be located on the opening H side of the insertion port contact member 50. More specifically, the foreign matter removal section 51 is attached to the inclined surface 32a of the inner circumferential surface 31a of the mounting member 30. The foreign matter removal section 51 is annular in shape and is fixed to the inner circumferential surface 2a of the receiving port 2 via the mounting member 30. The inner diameter of the foreign matter removal section 51 is smaller than the outer diameter of the insertion port 3. The foreign matter removal section 51 is made of an elastically deformable material. For example, the foreign matter removal section 51 is made of rubber. The foreign matter removal section 51 may be made of a material other than rubber, as long as it is an elastically deformable material.

[0075] Therefore, when the insertion port 3 is inserted into the receiving port 2, the foreign matter removal portion 51 comes into contact with the outer circumferential surface 3a of the insertion port 3. Thus, the foreign matter removal portion 51 is compressed radially between the outer circumferential surface 3a of the insertion port 3 and the inner circumferential surface 2a of the receiving port 2. In other words, the foreign matter removal portion 51 is pressed against the outer circumferential surface 3a of the insertion port 3 by the elastic restoring force of the foreign matter removal portion 51 in the radial inward direction. As a result, the inner circumferential surface of the foreign matter removal portion 51 and the outer circumferential surface 3a of the insertion port 3 are in close contact in the radial direction.

[0076] Since the foreign matter removal section 51 is fixed to the inner circumferential surface 2a of the receiving opening 2 via the mounting member 30, it does not move axially even when the insertion opening 3 moves axially. Furthermore, when the insertion opening 3 is slid axially relative to the foreign matter removal section 51, the foreign matter removal section 51 continues to press the outer circumferential surface 3a of the insertion opening 3 radially inward. For this reason, even when the insertion opening 3 is slid axially relative to the foreign matter removal section 51, no gap larger than the foreign matter G is created between the foreign matter removal section 51 and the outer circumferential surface 3a of the insertion opening 3. Therefore, when the insertion opening 3 is inserted into the receiving opening 2, the foreign matter removal section 51 removes the foreign matter G adhering to the outer circumferential surface 3a of the insertion opening 3.

[0077] Furthermore, as described above, the foreign matter removal section 51 is attached to the inclined surface 32a of the main body 31 of the mounting member 30. The inner diameter of the inclined surface 32a of the main body 31 decreases from one end in the axial direction toward the other. On the other hand, the inner diameter of the foreign matter removal section 51 before the insertion port 3 is inserted into the receiving port 2 is constant in the axial direction. Therefore, the radial thickness of the foreign matter removal section 51 decreases from one end in the axial direction toward the other.

[0078] Therefore, when the insertion port 3 is inserted into the receiving port 2, the axial end of the foreign matter removal portion 51, which has a smaller radial thickness than the axial end, is compressed more strongly in the radial direction than the axial end, as it is sandwiched radially between the outer circumferential surface 3a and the inclined surface 32a of the insertion port 3.

[0079] As a result, when inserting the insertion port 3 into the receiving port 2, the elastic restoring force that the outer circumferential surface 3a of the insertion port 3 receives from the foreign matter removal section 51 is greater when the insertion port 3 passes the other axial end of the foreign matter removal section 51 than when the insertion port 3 passes the one axial end of the foreign matter removal section 51. Therefore, the insertion port 3 can be inserted more easily into the one axial end of the foreign matter removal section 51, and foreign matter G adhering to the outer circumferential surface 3a of the insertion port 3 that slides against the other axial end of the foreign matter removal section 51 can be removed more reliably.

[0080] (Lubricant applied area) The lubricant application section 52 is a component that contacts the outer circumferential surface 3a of the insertion opening 3 inserted into the receiving opening 2, and applies the lubricant K onto the outer circumferential surface 3a of the insertion opening 3.

[0081] The lubricant K reduces the frictional resistance generated when the outer circumferential surface 3a of the socket 3 comes into contact with the contact portion 22a of the seal portion 22. The lubricant K is, for example, a lubricant for ductile iron pipe fittings. Any known configuration of lubricant K can be used as long as it is a material that reduces the frictional resistance generated when the outer circumferential surface 3a of the socket 3 and the contact portion 22a of the seal portion 22 come into contact. The lubricant may also be, for example, silicone grease.

[0082] The lubricant-coated portion 52 is attached to the inner circumferential surface 31a of the mounting member 30 so as to be located on the opposite axial side of the insertion port contact member 50. The lubricant-coated portion 52 is annular in shape and is fixed to the inner circumferential surface 2a of the receiving port 2 via the mounting member 30. The inner diameter of the lubricant-coated portion 52 is smaller than the outer diameter of the insertion port 3. A portion of the lubricant-coated portion 52 is positioned to overlap radially with the retaining portion 311 of the mounting member 30 and the insertion portion 21 of the receiving port groove of the sealing member 20.

[0083] The lubricant coating section 52 is made of a porous material that has many pores and is elastically deformable. Therefore, the lubricant coating section 52 can contain lubricant K in its pores. When the lubricant coating section 52 is compressed, for example, the lubricant K in its pores can be released to the outside. The lubricant coating section 52 is made of, for example, urethane rubber. The lubricant coating section 52 may be made of a material other than urethane rubber, as long as it is an elastically deformable porous material.

[0084] When the insertion port 3 is inserted into the receiving port 2, the lubricant application portion 52 comes into contact with the outer circumferential surface 3a of the insertion port 3. As a result, the lubricant application portion 52 is compressed radially between the outer circumferential surface 3a of the insertion port 3 and the inner circumferential surface 2a of the receiving port 2. This allows the lubricant application portion 52 to apply the lubricant K onto the outer circumferential surface 3a of the insertion port 3 that it is in contact with.

[0085] Since the lubricant application section 52 is fixed to the inner circumferential surface 2a of the socket 2 via the mounting member 30, similar to the foreign matter removal section 51, it does not move axially even when the insertion opening 3 moves axially. Therefore, when inserting the insertion opening 3 of the pipe W2 into the socket 2 of the pipe to be joined W1, the insertion opening 3 slides axially against the lubricant application section 52, allowing the lubricant K to be applied to the outer circumferential surface 3a of the insertion opening 3 by the lubricant application section 52.

[0086] The lubricant application section 52 is located in the axial direction opposite to the foreign matter removal section 51, which is in the axial direction of the socket 2. Therefore, the lubricant application section 52 contacts the part of the outer circumferential surface 3a of the socket 3 that is located in the axial direction opposite to the part where the foreign matter removal section 51 is in contact. As a result, when inserting the socket 3 of pipe W2 into the socket 2 of pipe W1 to be joined, the outer circumferential surface 3a of the socket 3 contacts the foreign matter removal section 51 and then contacts the lubricant application section 52. This allows the lubricant application section 52 to apply lubricant K to the outer circumferential surface 3a of the socket 3 after the foreign matter G has been removed.

[0087] The foreign matter removal portion 51 and the lubricant application portion 52 of the insertion port contact member 50 are each located on the opening H side of the receiving port 2 of the pipe W1 to be joined, rather than on the contact portion 22a of the sealing member 20. Therefore, the foreign matter removal portion 51, the lubricant application portion 52, and the contact portion 22a of the sealing member 20 are fixed to the inner circumferential surface 2a of the receiving port 2 so that they are aligned sequentially from the opening H toward the other axial direction, which is axially inward of the receiving port 2. As a result, the joint structure 1 is configured such that when the insertion port 3 of the pipe W2 is inserted into the receiving port 2 of the pipe W1 to be joined, the outer circumferential surface 3a of the insertion port 3 contacts the lubricant application portion 52, the lubricant application portion 52, and the contact portion 22a of the sealing member 20 in sequence.

[0088] The joint structure 1 according to the embodiment described above is a joint structure 1 having a slit 3 of a pipe W2, a receiving 2 of a pipe to be joined to the pipe W2, and an annular sealing member 20 that seals the space between the outer circumferential surface 3a of the slit 3 of the pipe W2 and the inner circumferential surface 2a of the receiving 2 of the pipe to be joined W1. The joint structure 1 has an annular slit contact member 50 fixed to the inner circumferential surface 2a of the receiving 2 of the pipe to be joined W1 at a position closer to the opening H of the receiving 2 of the pipe to be joined than the sealing member 20, so as to contact the surface of the outer circumferential surface 3a of the slit 3 that is located closer to the opening H of the receiving 2 of the pipe to be joined W1 than the surface of the receiving 2 that the sealing member 20 is in contact with.

[0089] According to the above configuration, when joining pipe W2 to pipe W1, the insertion opening contact member 50 contacts the outer circumferential surface 3a of the insertion opening 3 of pipe W2 before the insertion opening 3 of pipe W2 contacts the sealing member 20.

[0090] This allows for simultaneous pre-treatment, such as removing foreign matter G adhering to the outer surface 3a and applying lubricant K, and the insertion of the pipe W2's spigot 3 into the receiving end 2 of the pipe W1 to be joined. Therefore, the joining of the receiving end 2 of the pipe W1 and the spigot 3 of the pipe W2 can be performed efficiently. Moreover, in the joint structure 1 having the above configuration, the pre-treatment of the pipe W2's spigot 3 does not need to be performed by an operator in the excavated trench where the pipe W2 is located.

[0091] Therefore, it is possible to provide a joint structure 1 that reduces the burden on the worker and allows for easy and efficient joining of pipe W2 and pipe W1 to be joined.

[0092] Furthermore, in this embodiment, the insertion port contact member 50 includes an annular foreign matter removal portion 51 that contacts the outer circumferential surface 3a of the insertion port 3 to remove foreign matter adhering to the outer circumferential surface 3a of the insertion port 3.

[0093] As a result, when the insertion port 3 of pipe W2 is inserted into the pipe W1 to be joined, the foreign matter removal section 51 can remove foreign matter G such as dirt and dust adhering to the outer surface 3a of the insertion port 3 of pipe W2. Therefore, the burden on the worker to remove foreign matter from the outer surface 3a of the insertion port 3 is reduced, and a joint structure 1 is provided that allows pipe W2 and the pipe to be joined to be joined easily and efficiently.

[0094] Furthermore, in this embodiment, the insertion port contact member 50 is located further away from the opening H of the receiving port 2 than the foreign matter removal portion 51, and further includes an annular lubricant application portion 52 for contacting the outer peripheral surface 3a of the insertion port 3 and applying the lubricant K.

[0095] As a result, when inserting the insertion port 3 of pipe W2 into the pipe W1 to be joined, the lubricant K can be applied by the lubricant application port 52 to the outer surface 3a of the insertion port 3 of pipe W1 after foreign matter has been removed by the foreign matter removal port 51, thereby joining pipe W2 and the pipe W1 to be joined. Therefore, a joint structure 1 can be provided that reduces the burden on the worker in removing foreign matter and applying lubricant, and allows pipe W2 and the pipe W1 to be joined to be joined easily and efficiently.

[0096] Furthermore, in this embodiment, the joint structure 1 further includes an annular mounting member 30 for attaching the sealing member 20 to the inner circumferential surface 2a of the pipe to be joined W1. The foreign matter removal section 51 and the lubricant application section 52 are each mounted on the inner circumferential surface 31a of the mounting member 30 at a position closer to the opening H of the receiving end 2 of the pipe to be joined W1 than the sealing member 20, and are arranged axially in the order of the foreign matter removal section 51 and the lubricant application section 52 from the opening H of the receiving end 2 toward the axially inward side of the receiving end 2.

[0097] This allows the foreign matter removal section 51, the lubricant application section 52, and the sealing member 20 to be arranged sequentially from the opening H of the receiving end 2 of the pipe W1 to be joined toward the axial inward direction of the receiving end 2. Furthermore, by attaching the sealing member 20 to the inner circumferential surface 2a of the pipe W1 to be joined using the mounting member 30, and by attaching the foreign matter removal section 51 and the lubricant application section 52 to the inner circumferential surface 31a of the mounting member 30, the foreign matter removal section 51, the lubricant application section 52, and the sealing member 20 can be attached to the inner circumferential surface 2a of the pipe W1 to be joined using the mounting member 30.

[0098] Therefore, a joint structure 1 that allows joining pipe W2 and pipe to be joined W1 while removing foreign matter from the outer surface 3a of the insertion opening 3 of pipe W2 and applying lubricant can be more easily realized.

[0099] Furthermore, in this embodiment, at least one of the foreign matter removal section 51 and the lubricant application section 52 is arranged to overlap radially with respect to the mounting member 30 and the sealing member 20.

[0100] This makes it possible to achieve a configuration in which the foreign matter removal section 51 and the lubricant application section 52 can be arranged more compactly in the axial direction of the pipe W1 to be joined, relative to the sealing member 20 and the mounting member 30.

[0101] Therefore, with the above configuration, the axial length of the socket 2 can be shortened while achieving the sealing function by the sealing member 20 and the functions of removing foreign matter and applying lubricant to the outer surface 3a of the insertion opening 3 by the foreign matter removal section 51 and the lubricant application section 52 within the socket 2. Thus, the overall length of the pipe to be joined can be shortened while achieving the above functions.

[0102] The inner circumferential surface 31a of the mounting member 30 includes an inclined surface 32a in which the inner diameter decreases in the direction of insertion of the pipe W2 from the end on the opening H side of the receiving port 2. The foreign matter removal section 51 is elastically deformable in the radial direction and is fixed on the inner circumferential surface of the inclined surface 32a.

[0103] As a result, when inserting the insertion port 3 of pipe W2 into the receiving port 2 of pipe W1, the elastic restoring force that the outer surface 3a of the insertion port 3 receives from the foreign matter removal section 51 is small when the insertion port 3 passes the end of the receiving port 2 of the mounting member 30 on the opening H side, and increases as the insertion port 3 is inserted axially inward into pipe W1. Therefore, the insertion port 3 of pipe W2 can be easily inserted into pipe W1, and foreign matter G adhering to the outer surface 3a of the insertion port 3 can be removed more reliably by the foreign matter removal section 51.

[0104] Therefore, when joining the Socket 3 of pipe W2 to the Receptacle 2 of pipe W1 to be joined, foreign matter G adhering to the outer surface 3a of the Socket 3 can be removed more reliably while improving work efficiency.

[0105] (Pipe joining method) Next, the pipe joining method will be explained with reference to Figures 3 and 4A to 4F. Figure 3 is a flowchart of the pipe joining method. Figure 4A is a schematic cross-sectional view showing the placement of the sealing member 20 in the socket groove 15 of the socket 2 of the pipe to be joined W1. Figure 4B is a schematic cross-sectional view showing the attachment member 30 with the socket contact member 50 attached to it being attached to the pipe to be joined W1 in which the sealing member 20 is placed. Figure 4C is a schematic cross-sectional view showing the insertion of a pipe W2, in which foreign matter G is attached to the outer circumferential surface 3a of the socket 3, into the socket 2 of the pipe to be joined W1, to which the socket contact member 50 and the sealing member 20 are attached. Figure 4D is a schematic cross-sectional view showing the insertion of a pipe W2 into the socket 2 while removing the foreign matter G attached to the outer circumferential surface 3a of the socket 3 using the foreign matter removal unit 51. Figure 4E is a schematic cross-sectional view showing the process of inserting pipe W2 into socket 2 by applying lubricant K to the outer surface 3a of socket 3 from which foreign matter G has been removed using the lubricant application part 52, while bringing the outer surface 3a of socket 3 into contact with the contact part 22a of the sealing member 20. Figure 4F is a schematic cross-sectional view showing the state in which the pipe to be joined W1 and pipe W2 are joined. Note that each of the figures from 4A to 4F is a cross-sectional view in which pipe W2 and the pipe to be joined are cut in the axial direction by a plane containing the axis P of the pipe to be joined W1.

[0106] When the flow shown in Figure 3 starts (START), in step S1, the lock ring M is placed in the lock ring groove 14, and the seal member 20 is placed inside the pipe to be joined W1 such that the insertion part 21 of the seal member 20 into the receiving groove 15 is positioned as shown by the white arrow in Figure 4A.

[0107] Next, in step S2 of the flowchart shown in Figure 3, the insertion port contact member 50 is attached to the inner circumferential surface 31a of the mounting member 30. More specifically, as shown in Figure 4B, the foreign matter removal part 51 is attached to the inclined surface 32a of the inner circumferential surface 31a of the main body part 31 of the mounting member 30, and the lubricant application part 52 is attached to the inner circumferential surface 31a of the main body part 31.

[0108] Next, in step S3 of the flowchart shown in Figure 3, as indicated by the white arrow in Figure 4B, the mounting member 30 is inserted into the pipe to be joined W1, and the sealing member 20 is attached to the inner circumferential surface 2a of the receiving port 2 by the mounting member 30, and the insertion port contact member 50 is fixed to the inner circumferential surface 2a of the receiving port 2. In this way, the mounting member 30 fixes the insertion port contact member 50 and the sealing member 20 to the inner circumferential surface 2a of the receiving port 2 such that the foreign matter removal part 51, the lubricant application part 52 and the sealing part 22 of the sealing member 20 are aligned in order from the opening H of the receiving port 2 toward the other axial direction. Alternatively, the foreign matter removal part 51 and the lubricant application part 52 may be attached to the inner circumferential surface 31a of the mounting member 30 after it has been inserted into the pipe to be joined W1.

[0109] Next, in step S4 of the flowchart shown in Figure 3, the insertion port 3 of pipe W2 is moved axially to the other side relative to the receiving port 2 of the pipe W1 to be joined, as shown by the white arrow in Figure 4C. Note that the outer diameter of the insertion port 3 of pipe W2 inserted into the receiving port 2 is larger than the inner diameters of the foreign matter removal portion 51, the lubricant application portion 52, and the sealing portion 22 of the sealing member 20, which are fixed to the inner circumferential surface 2a of the receiving port 2.

[0110] Next, in step S5 of the flowchart shown in Figure 3, as indicated by the white arrow in Figure 4D, the insertion port 3 is moved to the other axial direction while the outer surface 3a of the insertion port 3 is brought into contact with the foreign matter removal section 51 of the insertion port contact member 50. As a result, the foreign matter G adhering to the outer surface 3a of the insertion port 3 is removed from the outer surface 3a of the insertion port 3 by the foreign matter removal section 51 and does not enter the receiving port 2.

[0111] Next, in step S6 of the flowchart shown in Figure 3, as indicated by the white arrow in Figure 4E, the socket 3 is moved further in the other axial direction while the outer surface 3a of the socket 3 is brought into contact with the lubricant application portion 52 of the socket contact member 50. The lubricant application portion 52 applies lubricant K to the outer surface 3a of the socket 3 that it has contacted. Thus, lubricant K can be applied to the surface of the outer surface 3a of the socket 3 after the foreign matter G has been removed by the foreign matter removal portion 51.

[0112] Next, in step S7 of the flowchart shown in Figure 3, as shown in Figure 4E, the Socket 3 is moved in the other axial direction while the outer circumferential surface 3a of the Socket 3 is pressed against the contact portion 22a of the seal portion 22 of the seal member 20. As described above, the outer circumferential surface 3a of the Socket 3 of the pipe W2 that contacts the contact portion 22a has had foreign matter G removed and lubricant K applied to it. This allows the outer circumferential surface 3a of the Socket 3 to slide smoothly against the contact portion 22a of the seal portion 22, and the Socket 3 can push the seal portion 22 in the other axial direction, which is the insertion direction, as shown by the black arrow in Figure 4E. In this way, after pre-treatment by removing foreign matter G from the outer circumferential surface 3a of the Socket 3 and applying lubricant K to the outer circumferential surface 3a of the Socket 3, the pipe to be joined W1 and the pipe W2 are joined with the seal portion 22 radially sandwiched between the receiving end 2 and the Socket 3 (see Figure 4F). After that, the flow shown in Figure 3 is terminated (END).

[0113] Step S1 corresponds to the sealing member installation process, step S3 to the insertion port contact member fixing process, steps S4 to S7 to the pipe joining process, step S5 to the foreign matter removal process, and step S6 to the lubricant application process.

[0114] The pipe joining method according to the embodiment described above is a pipe joining method in which the insertion port 3 of pipe W2 and the receiving port 2 of pipe to be joined are joined such that the space between the outer circumferential surface 3a of the insertion port 3 of pipe W2 and the inner circumferential surface 2a of the receiving port 2 of pipe W1 is sealed by an annular sealing member 20. The pipe joining method comprises: a sealing member attachment step S1 in which a sealing member 20 is attached to the inner circumferential surface 2a of the receiving end 2 of the pipe W1 to be joined; a insertion end contact member fixing step S3 in which an annular insertion end contact member 50 having an inner diameter less than or equal to the outer diameter of the insertion end 3 of the pipe W2 is fixed to the inner circumferential surface 2a of the receiving end 2 of the pipe W1 to be joined so as to be positioned closer to the opening H of the receiving end 2 of the pipe W1 than the sealing member 20; and pipe joining steps S4-S7 in which the insertion end 3 of the pipe W2 is inserted into the receiving end 2 of the pipe W1, and the outer circumferential surface 3a of the insertion end 3 of the pipe W2 is brought into contact with the inner circumferential surface of the insertion end contact member 50 and the sealing member 20 in that order, thereby joining the pipe W2 and the pipe W1 to be joined.

[0115] According to the method described above, when joining pipe W2 to pipe W1, the insertion opening contact member 50 contacts the outer circumferential surface 3a of the insertion opening 3 of pipe W2 before the insertion opening 3 of pipe W2 contacts the sealing member 20.

[0116] This allows the pre-treatment of the insertion port contact member 50, such as removing foreign matter G adhering to the outer circumferential surface 3a of the insertion port 3 and applying lubricant K, and the insertion of the insertion port 3 of pipe W2 into the receiving port 2 of pipe W1 to be joined, to be performed simultaneously. Therefore, the work of joining the receiving port 2 of pipe W1 and the insertion port 3 of pipe W2 can be performed efficiently. Moreover, in the joint structure 1 having the above configuration, the pre-treatment of the insertion port 3 of pipe W2 does not need to be performed by an operator in the excavated trench where pipe W2 is placed.

[0117] Therefore, it is possible to provide a pipe joining method that reduces the burden on workers and allows for easy and efficient joining of pipe W2 and pipe W1 to be joined.

[0118] In this embodiment, the Socket Contact Member 50 includes an annular foreign matter removal portion 51 for removing foreign matter G adhering to the outer circumferential surface 3a of the Socket 3 of the pipe W2, and an annular lubricant application portion 52 for applying lubricant K to the outer circumferential surface 3a of the Socket 3. In the Socket Contact Member Fixing Step S3, the Socket Contact Member 50 is fixed to the inner circumferential surface 2a of the pipe W1 to be joined such that the foreign matter removal portion 51, the lubricant application portion 52, and the sealing member 20 are arranged in order in the axial direction from the opening H of the receiving end 2 of the pipe W1 to be joined toward the axial inward side of the receiving end 2. The pipe joining process S4-S7 includes a foreign matter removal process S5 in which, when the insertion port 3 of pipe W2 is inserted into the receiving port 2 of pipe W1, foreign matter G adhering to the outer surface 3a of the insertion port 3 is brought into contact with the inner surface of the foreign matter removal section 51, thereby removing foreign matter G attached to the outer surface 3a of the insertion port 3; and a lubricant application process S6 in which, when the insertion port 3 of pipe W2 is further inserted into the receiving port 2 of pipe W1, lubricant application section 52, the outer surface 3a of the insertion port 3 that was in contact with the foreign matter removal section 51 in the foreign matter removal process S5 is brought into contact with the inner surface of the lubricant application section 52, thereby applying lubricant K to the outer surface 3a.

[0119] As a result, when inserting the insertion port 3 of pipe W2 into the pipe W1 to be joined, the lubricant K can be applied by the lubricant application unit 52 to the outer surface 3a of the insertion port 3 of pipe W2 after foreign matter has been removed by the foreign matter removal unit 51, thereby joining pipe W2 and pipe W1. Therefore, a pipe joining method can be provided that reduces the burden on the worker in removing foreign matter and applying lubricant, and allows pipe W2 and pipe W1 to be joined easily and efficiently.

[0120] Furthermore, in this embodiment, in the insertion port contact member fixing step S3, the foreign matter removal section 51 and the lubricant application section 52 are attached to the inner circumferential surface 31a of the annular mounting member 30 that fixes the sealing member 20 on the inner circumferential surface 2a of the pipe to be joined W1, such that the foreign matter removal section 51 and the lubricant application section 52 are aligned in the axial direction from the opening H of the receiving port 2 toward the axial inward side of the receiving port 2, at a position closer to the opening H of the receiving port 2 of the pipe to be joined W1 than the sealing member 20, respectively.

[0121] This allows the foreign matter removal section 51, the lubricant application section 52, and the sealing member 20 to be arranged sequentially from the opening H of the receiving end 2 of the pipe W1 to be joined toward the axial inward direction of the receiving end 2. Furthermore, by fixing the sealing member 20 on the inner circumferential surface 2a of the pipe W1 to be joined with the mounting member 30, and by attaching the foreign matter removal section 51 and the lubricant application section 52 on the inner circumferential surface 31a of the mounting member 30, the foreign matter removal section 51, the lubricant application section 52, and the sealing member 20 can be fixed on the inner circumferential surface 2a of the pipe W1 to be joined by the mounting member 30.

[0122] Therefore, a pipe joining method is provided that allows for easy and efficient joining of pipe W2 and pipe W1 while removing foreign matter from the outer surface 3a of the insertion opening 3 of pipe W2 and applying a lubricant.

[0123] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0124] In the above embodiment, the mounting member 30 is a member for fixing the sealing member 20 onto the inner circumferential surface 2a of the receiving port 2 and for fixing the insertion port contact member 50 to the inner circumferential surface 2a of the receiving port 2. However, the mounting member does not have to have the configuration of the above embodiment, as long as it is possible to fix the sealing member onto the inner circumferential surface of the receiving port and to fix the insertion port contact member to the inner circumferential surface of the receiving port. For example, a part of the mounting member may be fixed to the axial end face of the receiving port end of the pipe to be joined, or to the outer circumferential surface of the receiving port.

[0125] Furthermore, the mounting member may have only one of the functions: either fixing the sealing member onto the inner circumferential surface of the socket, or fixing the insertion contact member to the inner circumferential surface of the socket. Also, the joint structure may not have a mounting member. In this case, the sealing member and the insertion contact member are fixed onto the inner circumferential surface of the socket of the pipe to be joined without using a mounting member.

[0126] In the above embodiment, the mounting member 30 has a projection 33 that protrudes radially outward from the entire circumference of the outer circumferential surface of the main body 31 toward the receiving groove 15. However, the projection may protrude radially outward from a part of the outer circumferential surface of the main body toward the receiving groove.

[0127] In the above embodiment, the insertion port contact member 50 has a foreign matter removal section 51 and a lubricant application section 52. However, the insertion port contact member may have at least one of the foreign matter removal section and the lubricant application section. Also, the insertion port contact member may not have a foreign matter removal section and a lubricant application section.

[0128] In the above embodiment, the foreign matter removal section 51 and the lubricant application section 52 are made of an elastically deformable material. However, the foreign matter removal section does not have to be made of an elastically deformable material as long as it can remove foreign matter adhering to the outer surface of the pipe insertion opening. The lubricant application section does not have to be made of an elastically deformable material as long as it can apply lubricant to the outer surface of the pipe insertion opening.

[0129] In the above embodiment, a portion of the lubricant application portion 52 is arranged to overlap radially with the pressing portion 311 of the mounting member 30 and the insertion portion 21 of the receiving groove of the sealing member 20. However, a portion of the foreign matter removal portion may be arranged to overlap radially with the mounting member and the sealing member. The foreign matter removal portion and the lubricant application portion may be arranged to overlap radially with the mounting member and the sealing member. The foreign matter removal portion and the lubricant application portion do not have to be arranged to overlap radially with the mounting member and the sealing member.

[0130] In the above embodiment, the foreign matter removal unit 51 is attached to the inclined surface 32a of the inner circumferential surface 31a of the mounting member 30. However, the foreign matter removal unit does not have to be attached to the inclined surface. Also, the mounting member does not have to have an inclined surface on its inner circumferential surface. The lubricant application unit may be attached to the inclined surface of the inner circumferential surface of the mounting member. [Industrial applicability]

[0131] The present invention can be used in a joint structure and pipe joining method having a pipe insertion port, a receiving port of a pipe to be joined to the pipe, and an annular sealing member that seals the space between the outer circumferential surface of the pipe insertion port and the inner circumferential surface of the receiving port of the pipe to be joined. [Explanation of symbols]

[0132] 1. Joint structure W1 Joined pipe 2 socket 2a Inner surface 12 Socket end 12a Inner surface 14 grooves for lock rings 15 Socket groove W2 tube 3. Insertion port 3a Outer surface 20 sealing member 21 Insertion part inside the receiving groove 21a Inner surface 22 Seal part 22a Contact part 30 Mounting components 31 Main body 31a Inner surface 311 Retaining part 321 Socket contact part 32a Slope 33 Protrusion 50 Socket Contact Member 51 Foreign matter removal section 52 Lubricant application area H opening G Foreign object K lubricant M Lock Ring P axis

Claims

1. A joint structure comprising a pipe insertion port, a receiving port of a pipe to be joined to the pipe, and an annular sealing member that seals the space between the outer surface of the pipe insertion port and the inner surface of the receiving port of the pipe to be joined, The device has an annular insertion port contact member fixed to the inner circumferential surface of the receiving port of the pipe to be joined at a position closer to the receiving port opening of the pipe to be joined than the sealing member, so as to contact the outer circumferential surface of the insertion port that is located closer to the receiving port opening of the pipe to be joined than the surface in contact with the sealing member. Joint structure.

2. The joint structure according to claim 1, The insertion port contact member includes an annular foreign matter removal portion that contacts the outer circumferential surface of the insertion port to remove foreign matter adhering to the outer circumferential surface of the insertion port. Joint structure.

3. The joint structure according to claim 2, The aforementioned insertion port contact member is It further includes an annular lubricant application portion located further away from the receiving opening than the foreign matter removal portion, for contacting the outer circumferential surface of the insertion opening and applying a lubricant, Joint structure.

4. The joint structure according to claim 3, The pipe to be joined further has an annular mounting member for attaching the sealing member to the inner circumferential surface, The foreign matter removal section and the lubricant application section are mounted on the inner circumferential surface of the mounting member, respectively, at a position closer to the receiving opening of the pipe to be joined than the sealing member, and arranged axially in the order of the foreign matter removal section and the lubricant application section from the receiving opening toward the axial inward direction of the receiving opening. Joint structure.

5. The joint structure according to claim 4, At least one of the foreign matter removal section and the lubricant application section is arranged to overlap radially with respect to the mounting member and the sealing member. Joint structure.

6. The joint structure according to claim 4, The inner circumferential surface of the mounting member includes an inclined surface in which the inner diameter decreases from the end on the receiving port side in the direction of insertion of the pipe. The foreign matter removal unit is elastically deformable in the radial direction and is fixed on the inner circumferential surface of the inclined surface. Joint structure.

7. A pipe joining method comprising joining the spigot of a pipe and the socket of a pipe to be joined such that the space between the outer surface of the spigot of the pipe and the inner surface of the socket of the pipe to be joined is sealed by an annular sealing member, A sealing member mounting step involves attaching the sealing member to the inner circumferential surface of the receiving end of the pipe to be joined, A step of fixing an annular insertion contact member having an inner diameter less than or equal to the outer diameter of the insertion opening of the pipe, to the inner circumferential surface of the receiving opening of the pipe to be joined, such that the annular insertion contact member is positioned closer to the receiving opening of the pipe to be joined than the sealing member, A pipe joining process in which the pipe and the pipe to be joined are joined by inserting the insertion end of the pipe into the receiving end of the pipe, and bringing the outer surface of the insertion end of the pipe into contact with the inner surface of the insertion end contact member and the sealing member in that order, Having, Tube joining method.

8. In the pipe joining method described in claim 7, The insertion port contact member includes an annular foreign matter removal portion for removing foreign matter adhering to the outer surface of the insertion port of the pipe, and an annular lubricant application portion for applying lubricant to the outer surface. In the aforementioned insertion port contact member fixing step, The insertion port contact member is fixed to the inner circumferential surface of the pipe to be joined such that the foreign matter removal portion, the lubricant application portion, and the sealing member are arranged sequentially in the axial direction from the receiving port opening of the pipe to be joined toward the axial inward direction of the receiving port. The aforementioned pipe joining process is, A foreign matter removal step is performed in which, when the insertion end of the pipe is inserted into the receiving end of the pipe to be joined, the outer surface of the insertion end is brought into contact with the inner surface of the foreign matter removal section, thereby removing any foreign matter adhering to the outer surface of the insertion end. The process includes a lubricant application step in which, when the insertion end of the pipe is further inserted into the receiving end of the pipe to be joined, the lubricant is applied to the outer surface of the insertion end, which was in contact with the foreign matter removal part in the foreign matter removal step, by bringing the outer surface of the insertion end into contact with the inner surface of the lubricant application part. Tube joining method.

9. In the pipe joining method according to claim 8, In the aforementioned insertion port contact member fixing step, The foreign matter removal section and the lubricant application section are mounted on the inner surface of an annular mounting member that fixes the sealing member to the inner surface of the pipe to be joined, such that they are positioned closer to the receiving opening of the pipe to be joined than the sealing member, and are aligned axially in the order of the foreign matter removal section and the lubricant application section from the receiving opening towards the axial inward direction of the receiving opening. Tube joining method.

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